Organic electroluminescence refers to a phenomenon that a thin film device made of an organic photoelectric functional material emits light under the excitation of an electric field. According to different luminescent materials used in the preparation of the functional film, the thin film devices can be divided into organic electroluminescent diodes and polymer electroluminescent diodes. In recent years, organic electroluminescent diodes have made great progress, and satisfied practical requirements in the aspects of luminous brightness, luminous efficiency, and service life.
Electrochemical polymerization (ECP) refers to polymerization of a monomer occurring, after specific electrochemical electrolysis in an electrolytic cell with a proper electrolyte, on an electrode due to oxidation, reduction, or decomposition of the monomer into free radicals, ions, or the like. ECP can also be referred to as electrolytic polymerization, electropolymerization, or electron-initiated polymerization.
ECP has the following characteristics:
(1) reactions occur in a simple device under conditions easy to control, and thickness of a polymer film can be controlled;
(2) the polymer film has homogeneous thickness and high reproducibility;
(3) functional films of different structures and features can be obtained;
(4) various conductive polymers can be synthesized; and
(5) doping can be performed at the same time as the monomer is being polymerized.
In recent years, inkjet printing micro-manufacturing technology has been widely used in the field of manufacture of organic electroluminescent diodes. In preparing organic electroluminescent diodes through existing inkjet printing procedures, a crosslinkable hole transporting layer is usually prepared to solve the problem of mutual miscibility between layers in a solution processing device. However, it is difficult to effectively control a crosslinking degree and reactivity of a polymer or a small-molecule hole transporting material in a thin film state.